1. Field of the Invention
The present invention relates to a method of driving a heating unit for a fuel cell reformer, a reformer applied with the method for driving the heating unit, and/or a fuel cell system including the reformer.
2. Description of the Related Art
A fuel cell system (or fuel cell) is a power generation system for producing electrical energy using a hydrocarbon-based fuel.
Representative exemplary fuel cell systems include a polymer electrolyte membrane fuel cell (PEMFC) system and a direct oxidation fuel cell (DOFC) system.
The PEMFC system has power characteristics that are superior to those of conventional fuel cells, and has a low operating temperature and fast start and response characteristics. Because of this, the PEMFC system can be applied to a wide range of applications, such as portable electrical power sources for automobiles, distributed power sources for houses and public buildings, and small electrical power sources for electronic devices.
The PEMFC system is composed of a fuel cell stack for forming a fuel cell body (hereinafter referred to as a “stack” for convenience), a reformer that reforms the fuel to generate hydrogen gas and supplies the hydrogen gas to the stack, and an oxidant supplier for supplying an oxidant gas to the stack. The stack generates electrical energy through an electrochemical reaction of a reformed gas supplied from the reformer and an oxidant gas supplied from the oxidant supplier.
The reformer includes a burner (or a heating source) for generating heat energy through a catalytic oxidizing reaction of the fuel, and a reforming reaction part for generating a reformed gas from the fuel through a reforming reaction of the fuel by using the heat energy from the burner. In a conventional reformer, an oxidizing catalyst is required to be preheated at a high temperature since oxidization of a fuel gas by the oxidizing catalyst occurs at a high temperature in the burner of the reformer. Therefore, high heat efficiency is required in the above described fuel cell system.